Note 7 - Investment in and Advances to Real Estate Joint Ventures - Investment Details (Details) - USD ($)		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
The company's investment		$ 11,877,190,495	$ 12,653,444,998	$ 12,008,075,148	$ 11,568,809,126
Kim Pru and Kim Pru II [Member]
Average ownership interest	[1],[2]	15.00%
The company's investment	[1],[2]	$ 175,200,000	179,500,000
Kimco Income Fund [Member]
Average ownership interest	[2]	48.60%
The company's investment	[2]	$ 167,200,000	154,100,000
CPP [Member]
Average ownership interest	[2]	55.00%
The company's investment	[2]	$ 135,000,000	105,000,000
Other Joint Venture Programs [Member]
The company's investment	[3],[4]	93,500,000	45,300,000
All Equity Method Investments [Member]
The company's investment	[5]	$ 570,900,000	$ 483,900,000

[1] Represents four separate joint ventures, with four separate accounts managed by Prudential Global Investment Management, three of these ventures are collectively referred to as KimPru and the remaining venture is referred to as KimPru II.

[2] The Company manages these joint venture investments and, where applicable, earns acquisition fees, leasing commissions, property management fees, asset management fees and construction management fees.

[3] As of December 31, 2017, the Company had aggregate net deferred gains of $6.9 million relating to the disposal of operating properties prior to the adoption of ASU 2017-05. These deferred gains were included in the Company's investment above, of which $5.1 million related to KimPru II and $1.8 million related to Other Joint Venture Programs. Upon adoption, the Company recorded a cumulative-effect adjustment of $6.9 million to its beginning retained earnings as of January 1, 2018 on the Company's Consolidated Statements of Changes in Equity. See Footnote 1 to the Notes to the Company's Consolidated Financial Statements for further detail and discussion.

[4] During March 2018, the Company sold a portion of its investment in an operating property to its partner and amended the partnership agreement to provide for joint control of the entity. As a result of the amendment, the Company no longer consolidates the entity. As of the date of deconsolidation, the Company had an investment in this unconsolidated property of $62.4 million. See Footnotes 5 to the Notes to the Company's Consolidated Financial Statements for further detail and discussion.

[5] Representing 109 property interests and 23.2 million square feet of GLA, as of December 31, 2018, and 118 property interests and 23.5 million square feet of GLA, as of December 31, 2017.